1. Field of the Invention
This invention relates generally to a system and method for determining the state of health of a starter motor in a vehicle and, more particularly, to a system and method for determining the state of health of a starter motor in an internal combustion engine vehicle that employs a parameter estimation algorithm for determining starter motor resistance, inductance and back electro-motive force (EMF).
2. Discussion of the Related Art
As is well understood in the art, internal combustion engines typically employ a starter motor that is electrically coupled to a vehicle battery. When the ignition switch is turned on, battery power is provided to the starter motor, which rotates a motor shaft that rotates a flywheel. The flywheel rotates an engine shaft that in combination with fuel being provided to the engine causes the engine to be started so that operation of the engine can be sustained. The starter motor includes many components, including a motor armature, a motor stator, motor brushes, and other electrical components that define the motor. One or more of these components could fail as a result of many different situations where the starter motor will not operate properly, and thus, the vehicle may not start. For example, motor operation may be degraded or the motor may fail as a result of a dirty or bad brush, a short circuit of the armature coil, a weakened motor magnetic field as a result of the degradation of a permanent magnet in the motor, etc. Therefore, it is desirable to predict starter motor failure in advance of the actual failure so remedial actions can be taken before the vehicle driver is unable to start the vehicle.